Secondary or stobage batteby



B. FORD.

SECONDARY 0R STORAGE BATTERY. APPLICATION FILED MAR. 21, 1922.

1,433,681 Patented Oct. 31, 1922.

WIBQW Patented Oct. 31, 1922.

BRUCE FORD, OF PHILADELPHIA, PENNSYLVANIA.

SECONDARY OR- S'IORAGE BATTERY.

Application filed March 21, 1922.

To all whom it may concern Be it known that I, BRUCE Fons, a citizen of the United States, residing at Philadel phia, in the county of Philadelphia and State of Pennsylvania, have invented new and useful Improvement in Secondary or Storage Batteries, of which the following a. specification.

' In my Patent No. 1,185,788 of June 6th, 1916, I have shown, described and claimed a thread of which the slope or angle is substantially one in eight as a means for connccting storage battery nuts, parts or acces sorics of leaden material so that the parts can be repeatedly screwed and unscrewed because with a thread of such steep slope the leaden parts will not freeze together or become united. but can be drawn together to hold tight.

The present invention, while embodying or containing the invention of that patent, a. further improvement in such connec tions for storage battery parts or accessories in that it provides a shallow thread which is desirable because the diameters of the threaded parts should in some cases be limited, and in that it facilitates the casting of perfect and more durable threads.

The invention will be claimed at the end hereof but will. be first described in connection with the embodiments of it chosen for illustration in the accompanying drawings iormin g part hereof and in whicli Figure 1. an elevatioi'ial view of a leaden terminal having thereon a thread embodying featiures of the invention.

Fig. 2 is a sectional view drawn to an enlarged scale in order to illustrate the shape or form of the thread in cross-section.

Fig. 3 is a View similar to Fig. 1 but showing a single thread instead of two parallel threads.

F ig. 4 is a view similar to Fig. 2 showing a thread of. different form in cross-section.

and

Fi 5 a sectional view of a leaden con nection embodying features of the invention.

Referring to Figs. 1. and 2 there is a con tinuous double thread of appropriate slope and the thread is made with blunt face 1 and blunt root 2. Such a thread can be readily cast and it may be comparatively shallow yet sufficiently strong which is desirable because the diameters of the parts frequently require to be restricted. Referring to Figs. 3 and 4: the face 1" of the thread Serial No. 545,592.

is blunt and the root 2 of the thread is also blunt and there is but a single thread which is of appropriate slope. As shown in Fig. :2 the thread in cross-section tapers a little from the blunt root to the blunt face, whereas as shown in Fig. 4 this taper is absent. lVhere a single thread is employed as in Fig. 3 it can well be wider than where two threads are employed as in Fig. 1. The single thread may be substantially twice as wide as the double thread. Reference has been made to the appropriate slope of the thread which is such that the leaden parts on which the thread is provided can be drawn together to hold. tight and can also be repeatedly screwed and unscrewed without freezing or otherwise becoming united, and this slope may be described as substan tially one in eight, or another Way to describe it is to say that for a thread having a face diameter of seven-eighths of an inch and a root diameter of three-quarters of an inch there are about three to four turns per inch for each thread, which is a slope of about one in seven at the root for three per inch and about one in eleven at the face for four per inch, or substantially one in eight since it is several times the slope of ordinary threads of this depth. In the case of the double thread of Figure 1 the thread is about as vice as it is deep and in the case of the single thread of Fig. 3 the thread is quite wide in proportion to its depth.

In 5 a thread having a blunt face and a blunt root is shown in application to a leaden terminal 3 and a leaden nut 4 be tween which and a flange 5 the jar cover 6 and gasket 7 are clamped, and the nut at may be repeatedly removed and applied in order to detach the cover.

The term leaden is intended to include materials ordinarily used for the parts of lead storage batteries such as an alloy of lead and antimony.

I claim:

A detachable connection for storage battery parts or accessories comprising in combination. two leaden elements to be detachably connected and a thread of which the slope or angle is substantially one in eight and having a blunt face and a blunt root arranged between them whereby the diameter of the elements may be small in respect to the strength of the thread which can be readily cast.

BRUCE FORD. 

